Generally, according to a motor device used in a power seat device, a power window device or the like, a motor yoke and an end frame (housing)for closing an end portion of the motor yoke in an axial direction are coupled by crimping portions at three locations. However, the crimping portions are not formed at symmetrical positions relative to a motor rotating shaft, that is, at every 120 degrees centering on the rotating shaft. Therefore, angles of crimping are not uniform in a peripheral direction of the motor yoke and the crimp holding force of the motor yoke becomes nonuniform. When the crimping portions are formed at every 120 degrees centering on a rotating axis of the crimping portions, it is likely that a portion of the crimping portion positionally interferes with a guide portion formed on the end frame to engage with a transfer rail in manufacturing. Therefore, a length of the guide portion in a transfer direction cannot be made large. When the end frame is engaged with the transfer rail, the end frame cannot be moved to slide stably.
Further, when the end frame and the gear box are connected, axes thereof are deviated from each other. This brings about a disadvantage in a function such as operating sound or properties of the motor. Therefore, as shown by FIG. 18, when a resin-made end frame 41 is fitted with a bearing metal 42, there is a technology of forming a section of a fitting portion 41a of the resin-made end frame 41 not in a complete circle shape but in a polygonal shape. By forming the fitting portion 41a in the polygonal shape, an outer peripheral face of the bearing metal 42 is brought into contact with the fitting portion 41a by respective plane portion thereof in the polygonal shape. The axis center alignment of the fitting portion 41a and the bearing metal 42 can be carried out by partially establishing the accuracy by cutting to adjust a mold for forming the plane portions. Therefore, the axis center accuracy can be adjusted comparatively easily in comparison with the case of forming the section of the fitting portion 41a by a complete circle shape. However, it is desired to enable to adjust the axis center accuracy further easily.